Drive roller for moving heavy structures

ABSTRACT

A drive roller for moving heavy structures includes a body having a load bearing surface and a roller engaging surface. Rollers supported by endless link chains are moveable about the roller engaging surface of the body. A shaft is rotatably mounted on the body. A worm wheel is non-rotatably secured to and rotatable with the shaft. A worm gear engages the worm wheel. Rotation of the worm gear imparts a rotary motion to the worm wheel thereby rotating the shaft. A sprocket is non-rotatably secured to and rotatable with the shaft. The sprocket engages the endless link chains. Rotation of the shaft results in the sprocket driving the endless link chains and rollers about the body.

FIELD OF THE INVENTION

[0001] The present invention relates to a drive roller for moving heavy structures.

BACKGROUND OF THE INVENTION

[0002] U.S. Pat. No. 5,492,436 (Suksumake) discloses a drive roller assembly which includes a frame with rollers supported by endless link chains moveable about the frame. Also mounted on the frame are a motor and a worm gear. The motor rotates the worm gear about a substantially horizontal axis perpendicular to the drive rollers. As the worm gear turns, the fighting of the worm gear push against the rollers which move about the frame causing the drive roller assembly to move.

[0003] The drive roller assembly constructed in accordance with the teachings of the Suksumake reference loses significant energy to the forces of friction. As well as significant energy loss due to friction, the Suksumake reference does not possess the mechanical advantage to operate manually under load. The Suksumake reference requires additional equipment in the form of a motor and/or a gear reducer which reduces portability while increasing operating costs.

SUMMARY OF THE INVENTION

[0004] What is required is a more efficient configuration of drive roller for moving heavy structures.

[0005] According to the present invention there is provided a drive roller for moving heavy structures, which includes a body having a load bearing surface and a roller engaging surface. Rollers supported by endless link chains are moveable about the roller engaging surface of the body. A shaft is rotatably mounted on the body. A worm wheel is non-rotatably secured to and rotatable with the shaft. A worm gear engages the worm wheel. Rotation of the worm gear imparts a rotary motion to the worm wheel thereby rotating the shaft. A sprocket is non-rotatably secured to and rotatable with the shaft. The sprocket engages the endless link chains. Rotation of the shaft results in the sprocket driving the endless link chains and rollers about the body.

[0006] With the Suksumake drive roller, the fighting of the worm gear must engage the rollers. There is a significant energy loss due to friction between the fighting of the worm gear and the rollers. If resistance is encountered, such resistance tends to push the worm gear out of engagement with the rollers or results in a pinching of the rollers between the worm gear and the frame. In contrast, the drive rollers described above, provide a more efficient usage of the worm gear.

[0007] Although beneficial results may be obtained through the use of the worm gear, as described above, all drive rollers tend to follow the path of least resistance. This means that there is a frequent need to have the direction of the roller corrected as it moves along support rails. This involves removing the load from the roller, repositioning the roller and replacing the load, before transfer can resume. Even more beneficial results may, therefore, be obtained when rail engaging tracking guides are positioned on each side of the body. It is preferred that the spacing between the rail tracking guides be made adjustable, in order to adjust to the various sizes of rails that may be encountered and ensure a proper gripping action as wear occurs.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to in any way limit the scope of the invention to the particular embodiment or embodiments shown, wherein:

[0009]FIG. 1 is a right side elevation view of a drive roller constructed in accordance with the teachings of the present invention.

[0010]FIG. 2 is a top plan view of the drive roller illustrated in FIG. 1.

[0011]FIG. 3 is a rear end elevation view of the drive roller illustrated in FIG. 1.

[0012]FIG. 4 is a bottom plan view of the drive roller illustrated in FIG. 1.

[0013]FIG. 5 is a left side elevation view of the drive roller illustrated in FIG. 1.

[0014]FIG. 6 is a front end elevation view of the drive roller illustrated in FIG. 1.

[0015]FIG. 7 is a side elevation view, in section, of the drive roller taken along section lines A-A of FIG. 6.

[0016]FIG. 8 is a side elevation view, in section, of the drive roller taken along section lines B-B of FIG. 6.

[0017]FIG. 9 is a bottom plan view of the drive roller illustrated in FIG. 1, with chain tensioner and rail tracking guides.

[0018]FIG. 10 is a front end elevation view of the drive roller illustrated in FIG. 9.

[0019]FIG. 11 is a side elevation view, in section, of the drive roller taken along section lines C-C of FIG. 10.

[0020]FIG. 12 is a top plan view of the rollers illustrated in FIG. 9.

[0021]FIG. 13 is a top plan view of a second embodiment of a drive roller

[0022]FIG. 14 is a side elevation view, of the drive roller illustrated in FIG. 13, taken along section lines B-B of FIG. 13, with the gear case in the low mounted position.

[0023]FIG. 15 is a side elevation view, in section, of the drive roller illustrated in FIG. 13.

[0024]FIG. 16 is a side elevation view, in section, of gear housing, taken along section lines A-A of FIG. 13.

[0025]FIG. 17 is a side elevation view, of the roller drive illustrated in FIG. 13 with the gear case in high mount.

[0026]FIG. 18 is a rear elevation view of the roller drive illustrated in FIG. 17.

[0027]FIG. 19 is a bottom plan view of the roller drive illustrated in FIG. 13.

[0028]FIG. 20 is top plan view of the tracking mechanism of the roller drive, engaged on a rail.

[0029]FIG. 21 is a top plan view of the tracking mechanism illustrated in FIG. 20 in the retracted position.

[0030]FIG. 22 is a side elevation view of the tracking mechanism illustrated in FIG. 20, engaged on the rail.

[0031]FIG. 23 is a side elevation view of the tracking mechanism illustrated in FIG. 20 in the retracted position.

[0032]FIG. 24 is front elevation view of the tracking mechanism illustrated in FIG. 20, in the retracted position.

[0033]FIG. 25 is a side elevation view of the tracking mechanism illustrated in FIG. 20, engaged on the rail.

[0034]FIG. 26 is a front elevation view of the tracking mechanism illustrated in FIG. 20, in the retracted position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0035] The preferred embodiment, a drive roller for moving heavy structures generally identified by reference numeral 10, will now be described with reference to FIGS. 1 through 12.

[0036] Structure and Relationship of Parts:

[0037] Referring to FIG. 1, there is provided a drive roller for moving heavy structures 10 which includes a body 12 that has a load bearing surface 14 and a roller engaging surface 16. Referring to FIG. 2, body 12 has a first end 18, a second end 20 and opposed sides 22. Referring to FIG. 9, rail engaging tracking guides 24 are positioned on each of opposed sides 22. Guide wheels 26 are provided on rail engaging tracking guides 24.

[0038] Referring to FIGS. 3 and 4, rollers 28 which are supported by endless link chains 30 are moveable about roller engaging surface 16 of body 12. Referring to FIGS. 5 and 6, chain tensioners 32 engage endless link chains 30. Adjusting screws 33 are provided for adjusting chain tensioners. Peripheral chain guides 34 are also provided on opposed sides 22 of body 12.

[0039] Referring to FIG. 8, a shaft 36 with a shaft bearing 38 is rotatably mounted at second end 20 of body 12. Referring to FIG. 8, a worm wheel 40 is non-rotatably secured to and rotatable with shaft 36. A worm gear 42 engages with worm wheel 40, such that rotation of worm gear 42 imparts a rotary motion to worm wheel 40 thereby rotating shaft 36. Worm gear 42 is mounted on a drive shaft 44 inside of a gear housing 46 located at second end 20 of body 12.

[0040] Referring to FIG. 7, a first sprocket 48 is also non-rotatably secured to and rotatable with shaft 36. First sprocket 48 engages with endless link chains 30, such that rotation of shaft 36 results in first sprocket 48 driving endless link chains 30 and rollers 28 about engaging surface 16. Rollers 28 have axles 29 around which rollers 28 rotate. Link chains 30 are secured to axles 29 of rollers 28. Referring to FIG. 11, a second sprocket 50 engages with endless link chains 30 and rollers 28 toward first end 18 of body 12. A handle 52 is provided at second end 20 of body 12 although it will be appreciated that handle 52 could be placed at either first end 18, second end 20, or both.

[0041] Operation:

[0042] The use and operation of drive roller for moving heavy structures 10 will now be described with reference to FIGS. 1 through 12. Referring to FIG. 10, to transport a load on drive roller 10, rail engaging tracking guides 24 on opposed sides 22 of drive roller 10 are engaged with a support rail 54. Rail engaging tracking guides 24 are adjustable to accommodate the various sizes of support rails 54 which may be encountered. Guide wheels 26 are mounted on a bracket 56 which slides adjustable along a cross bar 58 that extends between rail engaging tracking guides 24. Guide wheels engage with support rail 54 to ensure a proper tracking movement of drive roller 10 along support rail 54. Rail engaging tracking guides 24 serve to maintain drive roller 10 in position with support rail 54 to keep drive roller 10 advancing in the desired direction. This eliminates the need to otherwise interrupt the transfer in order to correct the direction of drive roller 10. Referring to FIG. 12, endless link chain with rollers 28 can articulate a sufficient amount in either direction order to accommodate minor deviations in tracking. Referring to FIG. 5, chain tensioners 32 allow for the adjustment of the tension in endless link chain 30 to ensure optimal operation, although it will be appreciated that drive roller 10 can operate without this feature.

[0043] Referring to FIG. 10, once positioned on support rails 54, a load may be placed on load bearing surface 14 of drive roller 10. Referring to FIG. 8, drive shaft 44 can be rotated either by a manually operated crank or by a drive motor. Worm gear 42 rotates with drive shaft 44. As worm gear 42 is engaged with worm wheel 40, rotation of worm gear 42 imparts a rotary motion to worm wheel 40. As worm wheel 40 rotates, so does shaft 36. Referring to FIG. 7, rotation of shaft 36 results in first sprocket 48 driving endless link chains 30 and rollers 28 about engaging surface 16 to move a load placed on load bearing surface 14.

[0044] Variations:

[0045] Referring to FIGS. 13 through 26, there will now be described a second embodiment of the roller drive generally referenced by numeral 100. The components of the first embodiment 10 and second embodiment 100 detailed below will be identified by the same reference numerals as used in the description above, so that only the differences need to be identified and specifically described.

[0046] Referring to FIG. 13, second embodiment 100 is similar to first embodiment except it differs from first embodiment 10 in that drive shaft 44 is now has opposed ends 110, such that drive shaft 44 can be driven from either end by either a manually operated crank drive or a drive motor.

[0047] Another difference with second embodiment 100, is that shaft 36 can be positioned with worm 42 below the worm gear 40 as illustrated in FIG. 16, or above as illustrated in FIG. 17. This allows gear housing to be positioned on roller in a low mounted position as illustrated in FIG. 14 or a high mounted position as illustrated in FIG. 17. The benefit of being able to do so is that when gear housing 46 is positioned in the high mounting position on body 12 of roller drive 100 can be used on a surfaces such as a floor, as well as on a rail as described in first embodiment 10, whereas it is only suitable for use on a rail when gear housing 46 is mounted in the low mounted position on body 12.

[0048] Referring to FIG. 13, with second embodiment 100, a plate 112 is provided which pivots around a pivot point 113 within roller body 12. Referring to FIG. 26, two spring loaded arms 114 unfold to engage with support rails 54. Referring to FIGS. 20 through 26, shoes 116 are provided at a first end 118 of each of arms 114. A second end 120 of each arms 114 is pivotally secured to plate 112. Shoes 116 are held against support rails 54 by a spring 122. Shoes 116 are adapted to contact with support rails 54 in a way that will allow free movement on various widths of tracking guides 24. Referring to FIG. 21, arms 114 are retracted by spring 122 automatically when roller drive 10 is removed from tracking guides 24. Arms 114 will retract so that shoes 116 are clear of contact with either an underlying surface such as a floor, or support rails 54.

[0049] Referring to FIG. 19, with second embodiment 100, linked chains 30 would be assembled in a “laminated leaf” manner, with roller tubes 28 on either sided. This type of arrangement is used in applications where linked chains 30 must carry severe loads. The number of laminations increases with the width of linked chains 30 as the load increases. In second embodiment 100, first sprocket 48 is engaged with linked chains 30 rather than with rollers 28. This provides a strong positive engagement, and allows for a higher concentration of roller 28. By having rollers 28 positioned on either side of linked chains 30 a wider rolling surface is provided. The configuration in second embodiment 100 allows the rollers 28 and linked chains 30 to flex for tracking purposes.

[0050] Referring to FIGS. 14 and 26, during roller movement, shoes 116 engage with support rails 54 causing plate 112 to stay centered on support rails 54. Referring to FIG. 23, second sprocket 50 is mounted non-rotatably to a shaft 124, which is mounted rotatably to a brackets 126 provided on plate 112. Referring to FIG. 14, second sprocket 50 engages closely to width of linked chains 30 and maintains rollers 28 square and centered to plate 112 as illustrated in FIG. 19. Referring to FIG. 14, This action takes place before roller 28 engage with roller engaging surface 16 of roller device 100. and the tracking correcting action occurs as the roller 28 engage with and travel along roller engaging surface 16. Referring to FIG. 20, each roller 28 and associated linked chain 30 is articulated a small amount, and the accumulation of these small corrections provides the necessary tracking.

[0051] Referring to FIG. 13, as the roller drive 10 is used predominately in a forward direction only, plate 112, arms 114 and shoes 116 are mounted to first end 18 of roller drive 10, and provides tracking action when roller drive 10 is used that direction only.

[0052] In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.

[0053] It will be apparent to one skilled in the art that modifications may be made to the illustrated embodiment without departing from the spirit and scope of the invention as hereinafter defined in the Claims. 

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
 1. A drive roller for moving heavy structures, comprising: a body having a load bearing surface and a roller engaging surface; rollers supported by endless link chains moveable about the roller engaging surface of the body; a shaft rotatably mounted on the body; a worm wheel non-rotatably secured to and rotatable with the shaft; a worm gear engaging the worm wheel, such that rotation of the worm gear imparts a rotary motion to the worm wheel thereby rotating the shaft; and a sprocket non-rotatably secured to and rotatable with the shaft, the sprocket engaging the endless link chains, such that rotation of the shaft results in the sprocket driving the endless link chains and rollers about the body.
 2. The drive roller as defined in claim 1, wherein rail engaging tracking guides are positioned on each side of the body.
 3. The drive roller as defined in claim 2, wherein the rail engaging tracking guides are spring biased into an engaging position.
 4. The drive roller as defined in claim 2, wherein the spacing between the rail engaging tracking guides is adjustable.
 5. The drive roller as defined in claim 1, wherein the body has a handle.
 6. The drive roller as defined in claim 1, wherein chain tensioners engage the chains.
 7. The drive roller as defined in claim 1, wherein rollers are positioned on either side of the endless link chains.
 8. The drive roller as defined in claim 1, wherein the shaft can be driven from either end.
 9. The drive roller as defined in claim 1, wherein the body has peripheral chain guides. 